1. Field of the Invention
The present invention relates to a method for the time-sequential recording of three-dimensional images each comprising at least one first and one second partial image, with a single sensor having a number of pixels. In addition, the invention relates to a device for the time-sequential recording of three-dimensional images each comprising a first and a second partial image.
2. Description of the Related Art
With the 3D trend of cinemas in the broadcast sector but also for private use, not only image or film reproduction by means of 3D screens but also the solutions for stereoscopic image recording are required. Here the need is for compact and cost-effective solutions. One example of the use of 3D images or 3D films is the control of vehicles in which the driver has only a very restricted view toward the outside. Here there is a need for cost-effective and compact stereo data recording which is displayed to the driver in the interior of the vehicle and on the basis of which it performs control of the vehicle. This is the case for example for military vehicles such as tanks, for instance. Owing to the high costs of the cameras required for instance for the infrared range, it is expedient here to support the recording of stereo images by means of a single camera.
Another example of the use of 3D images or 3D films is the recording of magnified stereo images, during an operation by means of a stereo surgical microscope. In this case, a compact recording unit is required in order not to obstruct the surgeon. The requirement of compactness can be fulfilled by the arrangement of a single camera for both stereo channels.
What is common to the examples mentioned is that as efficient use as possible of the available light is desired. In the area of military applications, in particular this is desirable because the vehicles discussed often travel without illumination, and so as efficient use as possible of the light afforded entails a great advantage. In the area of surgical microscopes, too, as efficient use as possible of the light is advantageous in order not to burden the patients unnecessarily with light and in order to avoid damage to tissue, particularly in the case of interventions on the retina. Therefore, it is endeavored to obtain the highest possible luminous efficiency during the recording of a partial image in order, for example, to keep the exposure of the tissue as short as possible or to be able to use as much available light as possible in the shortest possible exposure times for recording the stereoscopic images.
The prior art discloses optical observation devices in which the stereoscopic partial beam paths are imaged onto a common image receiver by a common main lens. By way of example, U.S. Pat. No. 5,828,487 describes a stereoscopic observation system comprising a single observation beam path and a camera. A switchable diaphragm is arranged between the observation beam path and the camera and can be moved to and fro at high speed from a left position to a right position in the observation beam path. The stereoscopic partial images are thereby produced. The device can be operated with a video camera, wherein the diaphragm is synchronized with the image refresh frequency.
What is common to the devices from the prior art is that a diaphragm ensures that either light for a right or a left partial image of a stereo image reaches the sensor of the camera. Therefore, either a right or a left partial image is recorded at an arbitrary point in time. In order to be able to achieve a high image frequency during the recording of stereoscopic images with systems of this type, the image content of the sensor has to be shifted very rapidly into a buffer memory in order that the sensor is rapidly ready again for a new exposure. The memory content is then read from the buffer memory during the exposure for the next partial image and transferred to a computer. The buffer memory required firstly increases the costs of the camera, the camera becoming all the more expensive, the greater the speed at which it is intended to be possible to read the stereo images. Furthermore, the buffer memory has to be situated near the camera chip in order to enable lossless data transfer at high data rates, which has the effect that limits are imposed on reducing the camera volume.
Therefore, the available camera technology also imposes limits on the endeavor to utilize the light as optimally as possible during recordings of the stereoscopic images. This holds true particularly if, besides the price of the camera used, a compact structural size of the camera is also of importance.
In light of the prior art mentioned, it is an object of the present invention to provide an advantageous method for the time-sequential recording of 3-dimensional images with a single sensor.
It is a further object of the present invention to provide an advantageous device for the time-sequential recording of three-dimensional images.